A 4 year old boy was brought with history of low back pain of seven days' duration after a trivial fall. On examination the
child had tenderness in the lower lumbar spine. There was no paraspinal swelling or spinal deformity. The spinal movements
were globally restricted and there was no regional lymphadenopathy or any neurovascular deficit. Systemic examination revealed
no abnormality. Plain radiographs of the spine revealed a collapse of the L3 and osteopenia of L4 vertebral body (fig 1A and B). Haematological investigations showed a haemoglobin concentration of 100 g/l, leucocyte count of 7.2 × 109/l (polymorphs 83%, lymphocytes 12%, and eosinophils 4%), and an erythrocyte sedimentation rate of 70 mm at one hour. The
child did not attend follow up for a month, but later presented with insidious onset high grade fever not responding to salicylates.
On examination of the abdomen, the liver was just palpable. There was no splenomegaly; however, the cervical lymph nodes were
palpable. Repeat radiographs showed collapse of D9, D11, L2, L3 vertebral bodies (fig 2A, B, and C). A haemogram showed anaemia (haemoglobin 50 g/l), leucocyte count 12.7 × 109/l (polymorphs 22%, lymphocytes 76%, eosinophils 2%).

(A) Plain AP radiograph of the dorsal and upper lumbar spine after one month, (B) plain AP radiograph of the lower dorsal
and LS spine after one month, and (C) plain lateral radiograph of the dorsal and LS spine after one month.